What energy source drives the movement of groundwater?

The movement of groundwater is primarily driven by the force of gravity. Gravity pulls water downwards through the soil and rock layers, allowing it to infiltrate and move through the subsurface until it reaches a point of equilibrium, such as an aquifer or a discharge area like springs or rivers. As groundwater moves, it can travel through various types of porous materials, following the path of least resistance.

The role of gravity in groundwater movement is crucial. It governs both the direction and the speed of the water as it moves through the underground channels and spaces, filling aquifers and fluctuating with seasonal changes in precipitation and withdrawal by humans.

While other factors, such as heat and chemical reactions, can influence groundwater in various ways, they do not drive its overall movement. For instance, the heat from the Earth's core contributes to geothermal processes and can affect water temperatures but does not directly influence groundwater flow as gravity does. Similarly, wind currents and chemical reactions, while significant in other environmental contexts, do not play a direct role in the large-scale movement of groundwater beneath the Earth's surface.